Pressure-relation gage.



E. 6. Wm.

PRESSURE REUNION GAGE.

MPPUCATION FILED MAN. 2!. l9! 1.

Mented $1M. M, 1915;

2 SHEETS-SHEETI.

' ens arena" rnicu.

ERVIN e. BAILEY, 0F NEWTON, MAssAcHUsErrs.

PRESSURE-RELATION GAGE.

Application filed March 21,

sure relation gage, and is embodied in an instrument provided I with an indicating, and, if desired, a recording device arranged to express the relation or ratio of .a variabledifference, in pressures to other differences 'in pressure, Whether va'riableor constant, without necessarily expressing the actual pressures or pressure differences.

The'instruinent is adapted for various uses,'as', 'fore'xampleffor indicating'the in terna l conditions of fluid conducting conduits so far as'such conditions affect theresistanceto flow of thefluids,or for use in indicating the; proportional quantities of g "through separate ducts in. multiple. 3

While several differenttypes and forms of construction'can be used in'the practical embodiment ofthis invention, the operation in-all cases depends upon-the principle of balancing moments about a singleaxis by changing the magnitude of some of the forces or moment arms with respect to the others in accordance with any desired rate of angular rotation. The manner of apply; ing these forces is such that the amount of angular rotation of the shaft necessary to bring about a state of equilibrium isja meas-.' me of the degree of change which has taken place in the relation of various pressures to others,'and which change has caused the rotation of the shaft.' In some types of instruments the moment 'arms upon which one or more pressuresact are varied-with the angular rotation about the axis, while other moment arms'remain constant or vaiy at a different rate and in other types the moment arms upon which the various pressures act remain constant and the amount of force produced from any given pressures or'differences of pressures is changed by the rotation of the mechanism about the axis, while other forces remain constant or vary at a different rate at the same time.

F igpre l is a front view, partly in section;

Specification of Letters Patent.

withinhell 9, above the liquid;

1911. Serial to. 616,018.

of an instrument embodying the invention; Fig. 2-is asection, through the middle of Fig. 1; Fig. 3 is a detail, in perspective, showing the oscillating member, the pointer, and a portion of the dial; Fig. 4: is a ver tical section showing an instrument of modified construction; and Fig. 5 is a similar view 'showing a further modification.

While the use of this instrument is not limited to any one particular system, its

PatentedSept. 1a, 1915.

functions can bemore readily understood if described 1n connectlon .wlth one or more specific systems, such as a system involving a proportional flow of airandgas to a furnace through. ducts, and, as another example,

a system in which solid fuel is used in inclosed fuel beds. g

Referring to Figs. 1, 2 and 3,in the application of this type of instrument to a system in which it is desired to indicate the proportional flow of air and gas to a furnace, pipes 1 and are respectively connected to the dynamic and static nozzles of a Pitot tube.

inthe air duct, or any other equivalent device so that the difference between the pressures conveyed to the instrument these pipes is a function of the rate of flow of air to the furnace. Pipes 3 and 4 are connected into the gas duct in a similar manner, so that the difference between the pressures in them is a function ofthe rate of flow of gas to the furnace. The instrument consists of a closed case 5, having a partition 6, which.

divides the case and a vessel 7, containing aliquid, into two separate compartments. Within these compartments, two movable pressure actuated abutments, shown as bells '8 and 9 are so suspended by flexible connections from a sheave 10 and a cam 12 that their lower open endsdip into the liquid so asto seal the space within the bells. pipe 1 connects :into the compartment C011. taining the hell 9, while pipe 2 connects into the samecompartment, but is arranged so as to be in communication with the space,

In like manner, pipes 3 and 4 connect into the compartment containing the hell 8, so that in both cases the preponderance of pressure in the pipes land 3 over that in the pipes 2 and 4', respectively, exerts force which tends to move each bell downward. The sheave 10 and the cam 12' from which the bells 8 and 9 are respective y suspended, are fastened on an oscillatable member such as a shaft 13,

andthe sheave andcam are so shaped with The a relation to eachother that there is a definite relation between the lengths of their supporting radii for'any one position of the shaft, and this relation changes in a definite manner as the shaft rotatesp Attached-to the shaft 13 is a ca-in 'or; sheave 1 1, from which. is suspended fa' counterpoise; By

means ofa' 'fiexible'copnector. The cam 14 is so shaped with respect to the weight of for various positions ofj-the shaft that the moment produced by counterpois'e 15 acting upon the corresponding radius of sheave 14 will produce equilibrium of the entire moving mechanism for any position of the shaft 13. This also includes the change, in effective Weightspfthe'beHs and counterpoisedue to the variation -.in buoyancy for diftothe position ofshaft 13.

The momentsdiie to the iveights of all mechanism suspended from the shaft 13 beingbalanced for "any. angular position of the shaft, itis evidentjthat-the'shaft is free L to turn onits ia'xisr in" response to the mo:

inents due to the p t fferences of pressures Whichf'maybe applied to the-bells.. If the forces are .equal, the shaft Will turnon its ax'is' 'until the moment arms of the bells or the'ieflective radii of thecam 12' and the -sheave 10 areequal, or-i'f the-forces are un- .equal the shaft Willtake such a position-that 'tional'tosu'ch forces resulting from the difthe effective radii are inversely proporferences.fof pressures applied thereto. -By

corded. This indicated'or recorded relation can be denoted in any desired-units, 'such as'cubic feet of air per cubic foot of "tionfwhile' in other case's of pressure to another, etc.

gas, percentage of one pressure or difi'erence IILSOHIG cases it isfidesirable to have the bells 8 and 9 of unifoijna area of crosssect is necessary to vary the area-of one hell with respectrto the otherin order to secure the desired-relation between the variousppressures 1 Referring to Fig; 4, the modified instruv; ment shown is particularly adapted for use in indicating the relation eXistingbetween two-or more differences-of pressures where one pressure is common to all others so-far as dilferenceflof pressures is concerned, and.

it may be greaterthan some-and less than others'such as the case of a boiler'and furnace where it is desired to indicate the rela- 7 tion of the drop in pressure ac ss the. fuel bed to the drop across some other resistance in series therewith, such as that offered by the tubes of the boiler. Pipe 21 is connected into the uptake or the spaee beyond the boiler tubes, pipe 22 into'thefire box, pipe 23 into the ash pit or space beneath the grate, and each transmits the pressure from the respective parts of the boiler and furnace to the instrument. The instrument proper consists of a closed case 24 containing a liquidfin thelower part, into which bells 25 and 26 dip. Bell 25 is supported by pivot27- from the oscillating beam 28, which is mounted on the fixed pivot or shaft '29, and since the pipe 21 is connected to the space within bell 25 above the liquid, and

the pipe 22 is connected into the case 21 outside'of the bell 25, the preponderance of pressure is outside of the bell 25, so that I said bell tends to be forced downward in ferent depths of submersion corresponding accordaneewith the preponderance of pres sure in pipe 22 over that in the pipe 21.

tion on the beam 28 between the pivots 27 and 29 is fastenedfa cross arm 32, which has apivot 33 supporting thebell 26, and a pivot supporting -a counterweight The pipe 23 is connected to the space withln bell 26 above the liquid, and the pressure 'conveyed by pipe 22 acts upon the outside ofthebell 26 so that a' preponderance of pressure conveyed through the pipe 23 over' that conveyed through the pipe22 will tend to raise the bell 26 and more the beam in the direction opposite to that produced by the difference of pressures applied to hell 25; A counterweight 36 is supported from thepivot and counterbalances the moments produced by'the weight of bells 25 and 26 and other mechanism on the opposite side of the pivot 29 supporting the beam 28 when said beam is standing in its normal position, The weight 38 on the bell 26 is such as to overcome the efi'eet of the maximum difference between the pressures above .of bell'25 -.and its moment arin, as compared with the area of,-bell.26 and its moment arm, acertain relation may exist between the pressures'fcommunicated through the pipes-21, 22 and 23 without causing any unbalanced 'mdments or mot ion.- For instance,-if there is a certain desired relation between the drop in pressure across the fuel bed to the dropin pressure across the boiler tubes; the instrument would'be so adjusted thatbeam 28 would remain in its normal position so long as this relation between the different drops 1n pressures existed, regardless of the intensities of such pressures.

However, in case there is a deviation from this relation between the different drops in pressure, it is evident that there will be andecreased downward force exerted upon pivot 33 and beam 28, which tends to turn the beam clockwise about pivot 29, and during this movement the moment arm of hell 25 will remain practically the same, since the movement of the pivot 27 is, very nearly vertical. The pivot 83, however, is so positioned with relation to the pivot 29 that, in the movement of said pivot 33 it has a material lateral component as well as a vertical component, so that the effective moment arm of the bell 26 is increased with the movement and this increase in the moment arm of the net force acting upon pivot 33 causes an increase inthe moment of force,

as compared with the same force acting in the former position, and tends to restore equilibrium. The counterweight is so pivoted at 34 that as the beam rotates, the

point of support of the counterweight revolves about pivot 29 and the effective moment arm of-the counterweight is diminished as the moment arm of the bell 26 is increased, and vice versa. The actual weight of the counterweight 35 is so protlli portioned with respect to the weight of the bell 26 plus that of the weight 38 that equilibrium of moments due to the weights of the mechanism is substantially maintained for any angular position of the beam 28 within the intended range of the instrument, so that the position taken by the beam 28 is an indication of the amount of deviation which has taken place in the differences of pressure from any one ratio or relation of such differences. to thebeam 28 and moves over the scale 31 and thereby indicates .the proportional change in the relation of one difference of pressure to another from any desired relation for which the instrument is set. In the case of different boilers and different coals the relation of drop in. pressure across the fuel bed and the drop in pressureacross the boiler may vary, but this type of instrument may be used for any of these conditions by merely changing the position of the cross arm 32 on the beam 28; or by changing the area bell 26 with respect to the horizontal projection of the distances between pivots 29 and 33, and between the pivots 29 and 27, and also with respect to the area of the bell 25 and suitably changing the counterweight 35 andthe weight 36 The pointer 30 is attached which is hung on the end of the beam or the position of the weight 39, which may be considered as part of the weight 36; so that equilibrium is maintained, when the desired relation exists. The instrument will then indicate the nature and extent ofdeviations from the desired relation.

In some cases it is desirable to use an instrument of this type for indicating the relation between the drop in pressure across the fuel bed to the drop in pressure across the fuel bed added tothe drop in pressure across some substantially constant resistance in series therewith. such as that due to the boiler tubes. In this case the pressure in the ash pit is common to both differences of pressure, and this instrument would be slightly modified by. hanging, the pressure receiving bells from an oscillatable member consisting of a beam at opposite'sides of the ences of pressures which produce motion also causes a balancmg of moments by changing the intensity of force produced by any given difference in pressure, and retains substantially the same length of moment arms, so that the amount of motion is an indication of the amount of relative change in the differences of pressures.- This instrument is provided with a closed case 40, and a fixed pivot 41 supporting a beam 4L2; and from pivots 43 and 44 on this beam, are supported bells 45 and 46, respectively, which bells dip intoand are sealed by the liquid conspace within the case 140, outside of the bells, is connected by a pipe 47 with the ash pit. The space within the bell 45 above the liquid is connected by a pipe, 48 with the tained in the lower part of the case. The a fire box. The space within the bell 4G and i above the liquid is connected by a pipe -19 to the uptake. The preponderance of pres-- sure in the ash pit over the pressure in the" fire box acting uponthe bell l5 will cause a resulting force to be exerted downwardly on pivot 43, which force is in proportion to the difference between the pressuresacting upon the bell 45; and the said force will tend to cause movement of the beam 4 2 about its pivot 41. In like manner, the preponderance of pressure 'C()I'l1l1'lll11l(iltt3(l through the pipe 47 over that conmnmicated through the pipe 49, in acting upon the bell 46, will cause a resulting force acting downon the pivot 44 and will tend to cause the rotation of the beaifi in theopposlte d 1- rection'. In the drawing, the bell 45 is shown as having a constant area while 1 the area 'of the bell 46 varies with respect to its height, so thatas the beam. 42 moves, the'bell surface'of the 'liguid, and is acted on by .the

The betweenq the. pressures above andjbelowthe bell 546 is represented by' the] volume of liquid-sustained within the bell 46 above thel'evje'l of the liquid in the space surrounding the saidbell. The height at which this {liquid stands jwithin thejbell 46, as'compared --gwith1the'height'of the liquid outside of the ',ffbell,*;is definitely proportional to the dif-' 20' .through-the -pipes 47 and 49 being 'variabl fer'ence" ini -the' pressures communicated but the area iththe height-of the bell 46,-: it is obviate that the; force "resulting.

from' a'ny jdiflence of the flpressu'res' trans "mit ed nip 7 and e chee y-w th th am 42. The instrument is at while; any given relation p sit on c .so adjuste exists;v between-F the various pressures com-fv municatedj'tothls 1nstrument,--f{the movable partswill remain in. equilibrium. If,!l iowever, i a ny. chan' e. in this relatiohptakes placesnakes t e difference io f pressures acting on the" bell 46 becoming greater,

, while thedifi'eren'ce in pressures' acting on the ,bell' remains the. same, 1 an unbalanced -\moment-is produced, andfthe'be'am 42will befturned bolintenclockwise until the bell '46 becomes flinore" deeply submerged'fin the liquid; arid'the-mean area of the liquid sus .iainediwithin"theabell will decrease as the islowered, so that the volume will re isrn comesto' rest through the .restoration fastate ofequilibrium; By properly prothe parts of the etween thejpivots 41 and 43,-andi the pivots 41 and 44, and also properly proportioning the :variable area of cross section of the bell 46,.and theQcase 40 at. the surface of theliq uid thev instrlfment' can be arranged to indicate-the nature and extent of variation fromiany desired re-.- lation between the" various pressures communicated within reasonable limits of. accu-' racy. The position taken by thebeam 42' is denoted by.ithe.pointer.50 on the scale 51,

1; and a recording attachment may be :used

- in a similar "manner.

the relation which itis desired to have exist betweenthe'various pressures for any given .p'osit'ionrof the pointer with respect to the, scale 51, it :is'only necessary 'to' raise or it vyhich may be' accomplished by sliding the lower'the bell ,46 with respect to the liquid,

orce due to -any 'diflerence n'substantially constant, and the'mechw In orderto change support for said bell in the pivot block 52, or, leaving this the same, by merely changing the amount of liquid in the case. The bell '45 may be similarly adjusted in the pivot block 53.

In cases where the pressure applied through the pipe 47 is greater than the pressure applied through the pipe'49, .but is less that the pressure applied through the pipe 48, the pivots 43 and 44 would both be loand the resulting forces would then tend to cause" rotation in opposite directions about the pivot 41 in a manner similar to that described in connection with Fig.4.

Bells having a variable relative area of cross section may be used in types of instruments illustrated in Figs. 1, 2 and 3, and constant radius sheaves used in either case, 'or if a more complicated relation is desired or certain corrections are to be made, a comcated upon the same side of the pivot 41,

bination of variable area bells supported from sheaves-of variable radii-may be used in order to accomplish the desired results. In all the types of machines illustrated in this application, the moments produced by I differences in pressures automatic ly bal- J 'ance themselves by changing -eit er the lengthof .moment arms upon which the forces act, or else by changing the force due a to any given difi'erence of pressures in respouse to the movement of some part of the mechanism so that the amount of motion will indicatethe nature .and extent of the change in the relation between the various pressures. a

WhatIclaim is: 1

' 1. In a pressure relation gage, the combination with bell-shaped abutments adapted to receive fluid pressures on opposite sides;

of an oscillatable indicating member; means for connecting the said abutments to the indicating member at points away from the axis of oscillation, whereby moments are.

produced by the pressures acting onsaid abutments, respectively, which moments tend to move said indicating member'in' opposite directions means forbalancing said moments to establish a state of equilibrium; and means for maintaining said moments in a state. of equilibrium by. progressively, v'avarious pressures applied.to opposite sides of the diflerent abutments.

2. In a pressure relation gage, the combination with a plurality of movable abutm'ents each adapted to receive fluid pressures on opposite sides, of an oscillatable in? I dicating member; means 'for connecting said abutments to said oscillatable member,

whereby moments about a common axis aec at Y the moment arms through which the pressure actuated devices operate; and means ,of rotation are produced by the pressures devices connected, respectively, with said projecting parts which constitute the moment arms through which the pressure actuated devices operate; and means whereby one moment of force is varied with relation to the other moment of force, in response to the movement of the said member.

4. In' a pressure'relation gage, the c'ombibination with an oscillatable member provided .with projecting parts; of pressure actuated devices connected, respectively, with said projecting parts which constitute whereby the relative lengths of the saidmoment arms are varied in response to the movement of the member around its axis.

5. In a pressure relation gage, the combination with bells adapted to receive pressures on opposite surfaces, of pipes or ducts affording communication between sources of pressure and the said bells; an oscillatable indicating member connected with said bells at different points away from its axis whereby moments are produced by the pressures acting on said bells which tend to rotate the said member 1n opposite "directions; and means whereby the said moments are varied with relation to each other in response to the movement of the oscillatablemember, so that I a'state of equilibrium will be reached and indicated when the position of said oscillatable indicating member denotes a definite relation between the pressure difl'erences. i

In testimony whereof, I have signed my name to this specification in the presence of two subscribing'witnessesn a ERVW G. BAILEY.

Witnesses:

. JAs. J. MAnoNnY, W. E. .CovENLY. 

